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home brew dyno
Posted: Mon Nov 16, 2009 2:08 am
by buzzawak
I asked this over on greybikes but did not get a single responce.
I have been looking into home brew dynos and found a few interesting sites that talk about the "home dyno" or "Streetdyno" which uses the weight of the car/bike as the load. You record the engine RPM and software to calculate the HP from the acceleration
http://www.ontrackdigital.com/dynographsandtables.html
http://members.fortunecity.com/jasoncuadra/id47.htm
StreetDyno
Wondering if anyone here has any experence with the "home dyno" or "Streetdyno"?
Re: home brew dyno
Posted: Mon Nov 16, 2009 1:39 pm
by NoNothing
Ive heard plenty of great things about these. While there is a margin of error with them, they get you REALLY close to an accurate result, within 1% is what I hear regularly.
I use an iPhone app called PocketDyno.
Basically, I set the app up with how much my bike and I weigh all together and when Im ready start the run. It uses the accelerometers (not GPS!) to calculate how much power Im putting out by the G forces and distance I have covered in what time (since it can take all those variables, time, distance, acceleration and weight, it can calculate power accurately). It then gives me a readout of my G's, 1/4th mile time, 0-60, 0-100, 1/8th mile, 1/4th mile, and of course horsepower.
I love the app, I can stick it to my tank with a magnet holder and Im good to go. Its not as good at the range of power like a normal dyno would be, but I want to no my peak and try to improve my 1/4th mile times.
I highly recommend it. I have not taken my bike to an actual dyno to have it tested, but from all the comparisons Ive seen online Im MORE than confident in this app.
There are also stand alone systems that do the same thing, but they run north of $100 and are usually built for cars so you'll have to do some inventive mounting on your bike.
Re: home brew dyno
Posted: Mon Nov 16, 2009 2:33 pm
by kilika2
nonothing,
Isn't there an app to that will calculate lean angle and the g forces on the turn. I remember Y_G posting something about this recently and wondered if you tried/have/are talking about that app?
Chris.
Re: home brew dyno
Posted: Mon Nov 16, 2009 3:42 pm
by NoNothing
kilika2 wrote:nonothing,
Isn't there an app to that will calculate lean angle and the g forces on the turn. I remember Y_G posting something about this recently and wondered if you tried/have/are talking about that app?
Chris.
I haven't heard of it, but Im gonna try to find the app/post now!
I dont see how you could calculate lean angle since the lateral G's would upset the accelerometer would it not? I dont know for sure.
Ill let you know if I find anything.
Re: home brew dyno
Posted: Mon Nov 16, 2009 3:45 pm
by yamaha_george
kilika2 wrote:nonothing,
Isn't there an app to that will calculate lean angle and the g forces on the turn. I remember Y_G posting something about this recently and wondered if you tried/have/are talking about that app?
Chris.
Hi Shred posted about it too.
Trick is to launch cleanly (no wheel lift) and use a straight road.
You can plot the run over Exactly the same bit time & time again with GPS.
Re: home brew dyno
Posted: Mon Nov 16, 2009 3:50 pm
by kilika2
viewtopic.php?f=2&t=4934&p=52482&hilit=iphone#p52482
That's the link, if you couldn't find it buzzawak. Also I wondered about the accelerometer part of it. Maybe it would explain something, like you can't accelerate during the turn, I don't know. Let us know what you find out, I might be interested in this later on.
Edit* I did a search for iPhone on the main forum so it takes you to the bottom of the page, but I'm sure you figured that out.
Chris.
Re: home brew dyno
Posted: Mon Nov 16, 2009 3:55 pm
by yamaha_george
kilika2 wrote:viewtopic.php?f=2&t=4934&p=52482&hilit=iphone#p52482
That's the link, if you couldn't find it buzzawak. Also I wondered about the accelerometer part of it. Maybe it would explain something, like you can't accelerate during the turn, I don't know. Let us know what you find out, I might be interested in this later on.
Edit* I did a search for iPhone on the main forum so it takes you to the bottom of the page, but I'm sure you figured that out.
Chris.
The app works on other fones too so look around !!!
Re: home brew dyno
Posted: Mon Nov 16, 2009 3:59 pm
by kilika2
I would buy it in a heart beat if it worked for my Samsung Eternity, I imagine you have to have something that the accelerometer can run off of. My phone is tilt sensitive but I don't think that good.
Chris.
Re: home brew dyno
Posted: Mon Nov 16, 2009 4:02 pm
by yamaha_george
kilika2 wrote:I would buy it in a heart beat if it worked for my Samsung Eternity, I imagine you have to have something that the accelerometer can run off of. My phone is tilt sensitive but I don't think that good.
Chris.
Chris,
go to the app designers web site it has a list of fones it will work with I seem to remember you have to dig around a bit to get there